Choke is a relatively common condition in horses. It occurs when a mass of food or a foreign body blocks the horse’s oesophagus (gullet), the tube that takes food from the back of the mouth (pharynx) to the stomach. Choke may be partial or complete.
The most common causes are a greedy horse attempting to swallow hay without chewing it thoroughly, swallowing food or other material which is either too dry or too coarse (most commonly hay), or food which swells rapidly once chewed (typically sugar beet) so that its passage down the oesophagus is slowed or stopped. It can also occur in foals who are given access to dry, coarse hay or straw. Any pre-existing condition which interferes with the horse’s ability to swallow, such as sedation, an injury to the neck or oesophagus, grass sickness, botulism, etc., can predispose a horse to choke.
The most visible signs are usually a discharge of saliva and feed material from the nostrils and/or mouth, depression and apparent difficulty in swallowing. When first ‘choked’ some horses will panic, making repeated unsuccessful efforts to swallow, or will cough and ‘gag’ as though trying to clear something from the back of the throat.
If the condition has gone unnoticed by the owner, the horse may become dehydrated and severely depressed. Although many cases clear on their own, and few are serious, it is possible for the oesophagus to rupture, and for death may follow due to shock and infection. While this is not common, the possibility does mean that the condition is classed as an emergency. if you think your horse has choke, please call us immediately.
How is choke diagnosed?
We will normally pass a stomach tube via a nostril into the oesophagus to confirm that something is obstructing passage into the stomach. This examination will determine at what level the blockage has occurred, how solid it feels and if it can be gently massaged to pass on into the stomach.
In most cases the saliva that is continually produced in the mouth will gradually lubricate the offending obstruction, eventually allowing its passage to the stomach. We may help speed this passage by administering a sedative or a spasmolytic injection to help relax the oesophagus. Sometimes, this is all that is required.
In other cases the obstruction can be gently encouraged to move on down into the stomach with the help of the stomach tube. If this cannot be achieved easily the horse is sedated and the obstruction flushed with water and lubricant via the stomach tube. Fluid is gently pumped in via the stomach tube and allowed to run out, gradually flushing some of the obstructing material out. This can be a long process and patience is needed to avoid damaging the oesophagus.
In some uncooperative or solidly-obstructed cases, or where a horse is panicked, it may be necessary to anaesthetise the horse to allow flushing to be performed safely and thoroughly. Once the choke is cleared the horse should be fed sloppy feeds or grass for several days to allow any local swelling to subside.
The most important complication is oesophageal rupture either as a direct result of the obstruction or following attempts to dislodge it.
Another possible complication is pneumonia. Occasionally, the horse may aspirate (breathe in) fluid and/or food material into the trachea (windpipe) and lungs, causing infection which may be fatal.
Horse owners can help prevent choke by:
- Soaking dry feed thoroughly to allow them to swell before they are eaten and swallowed.
- Ensuring regular routine dental care to allow the horse to chew food thoroughly and effectively before it is swallowed. Injuries to the insides of the cheeks, caused by sharp teeth, will cause discomfort and may discourage a horse from chewing food properly.
- Provide permanent access to clean water to encourage the horse to drink normally.
- Some horses tend to choke on a particular feed. Once this is recognised, access should be avoided.